Autonomously acting robot that understands physical contact

ABSTRACT

A planar touch sensor (an electrostatic capacitance sensor) for detecting a contact by a user on a body surface is installed on a robot. Pleasantness and unpleasantness are determined in accordance with a place of contact and a strength of contact on the touch sensor. Behavioral characteristics of the robot change in accordance with a determination result. Familiarity with respect to the user who touches changes in accordance with the pleasantness or unpleasantness. The robot has a curved form and has a soft body.

RELATED APPLICATIONS

The present application is a continuation of International ApplicationNo. PCT/JP2017/025859, filed Jul. 18, 2017, which claims priority fromJapanese Application No. 2016-142060, filed Jul. 20, 2016, thedisclosures of which applications are hereby incorporated by referenceherein in their entirety.

TECHNICAL FIELD

The present invention relates to a robot that autonomously selects anaction in accordance with an internal state or an external environment.

BACKGROUND ART

A human acquires various items of information from an externalenvironment via sensory organs, and selects an action. There are timeswhen an action is consciously selected, and times when an action issubconsciously selected. A repeated action becomes a subconscious actionin time, and a new action remains in a consciousness region.

A human believes that he or she has a will to freely select his or herown action, that is, that he or she has a free will. A reason that ahuman harbors an emotion such as affection or enmity toward anotherperson is that he or she believes that the other person also has a freewill. A person that has a free will, or at least an existence that canbe supposed to have a free will, is also an existence that eases aperson's loneliness.

A reason that a human keeps a pet, more than whether or not the pet isuseful to the human, is that the pet provides solace. It is preciselybecause a pet is an existence that to a greater or lesser degree createsan impression of having a free will that the pet can be a good companionto a human.

Meanwhile, for various reasons such as not being able to securesufficient time to look after a pet, not having a living environment inwhich a pet can be kept, having an allergy, or hating the thought ofbeing parted by death, there are many people who give up on keeping apet. If there were a robot that performed the role of a pet, it may bethat people who cannot keep a pet would also be provided with the kindof solace that a pet provides refer to JP-A-2000-323219).

SUMMARY OF INVENTION Technical Problem

Although robot technology has advanced swiftly in recent years, thetechnology has not advanced so far as to realize a presence as apet-like companion. This is because it cannot be thought that a robothas a free will. A human, by observing an action such that it can onlybe thought that a pet has a free will, feels the existence of a freewill in the pet, empathizes with the pet, and is given solace by thepet.

Consequently, it is thought that if there were a robot that hashuman-like or animal-like behavioral characteristics, in other words, arobot that can autonomously select a human-like or animal-like action,empathy toward the robot could be greatly increased.

The invention, having been completed based on the heretofore describedidea, has a main object of providing technology for causing behavioralcharacteristics of a robot to change by coming into contact with aperson.

Solution to Problem

An autonomously acting robot in an aspect of the invention includes asensor that detects a contact by a user on a body surface of the robot,a recognizing unit that determines an affection expression level inaccordance with a contact place and a contact strength, and an operationcontrol unit that causes behavioral characteristics of the robot tochange in accordance with the affection expression level.

An autonomously acting robot in another aspect of the invention includesa sensor that detects a contact by a user, an operation control unitthat selects a motion of the robot in accordance with the contact, adrive mechanism that executes the motion selected by the operationcontrol unit, and an outer skin formed of an elastic body.

The sensor is formed as a curved sensor that covers the outer skin.

An autonomously acting robot in another aspect of the invention includesa planar sensor installed on a body surface of the robot and detecting acontact on the robot, an operation control unit that controls anoperation of the robot in accordance with the contact on the robot, anda drive mechanism that executes an operation specified by the operationcontrol unit.

The robot has a curved body surface. The sensor is installed along thecurve of the body surface of the robot.

An autonomously acting robot in another aspect of the invention includesa recognizing unit that recognizes a lifting and hugging of the robot,an operation control unit that selects a motion of the robot, and adrive mechanism that executes the motion selected by the operationcontrol unit.

The recognizing unit categorizes aspects of lifting and hugging intomultiple kinds. The operation control unit selects a motion inaccordance with the kind of lifting and hugging from among a multiple ofmotions responding to the lifting and hugging.

Advantageous Effects of Invention

According to the invention, empathy toward a robot is easily increased.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a front external view of a robot.

FIG. 1B is a side external view of a robot.

FIG. 2 is a front external view of the robot when wearing clothing.

FIG. 3 is a sectional view schematically representing a structure of therobot.

FIG. 4 is a configuration diagram of a robot system.

FIG. 5 is a schematic view of an emotion map.

FIG. 6 is a hardware configuration diagram of the robot.

FIG. 7 is a functional block diagram of the robot system.

FIG. 8 is a sectional enlarged view of a body.

FIG. 9 is a flowchart showing a process when a contact is detected.

FIG. 10 is a functional block diagram of the robot system in a firstworking example.

FIG. 11 is an external view of an eye image.

FIG. 12 is a first conceptual view of when hugging the robot.

FIG. 13 is a second conceptual view of when hugging the robot.

FIG. 14 is a data structure diagram of a motion selection table.

DESCRIPTION OF EMBODIMENTS

In general, a person expresses an emotion toward a companion bycommunication via physical contact. A person subconsciously carries outan action of bringing bodies or portions of skin into contact by hugginga companion, rubbing cheeks, stroking a head, or the like, in accordancewith his or her own emotion. The same applies when the companion is arobot, and it is supposed that the more a user feels empathy toward therobot, and sees the robot as a living creature rather than as a meremachine, the more noticeable a desire for physical contact becomes. Arobot in this embodiment recognizes physical contact from a user,understands an emotion of the user toward the robot from the physicalcontact, and changes a behavioral aspect.

FIG. 1A is a front external view of a robot 100. FIG. 1B is a sideexternal view of the robot 100.

The robot 100 in this embodiment is an autonomously acting robot thatdetermines an action or gesture based on an external environment and aninternal state. The external environment is recognized using variouskinds of sensor, such as a camera or a thermosensor. The internal stateis quantified as various parameters that express emotions of the robot100. These will be described hereafter.

With indoor action as a precondition, the robot 100 has, for example, aninterior of an owner's home as an action range. Hereafter, a humaninvolved with the robot 100 will be called a “user”, and a user forminga member of a home to which the robot 100 belongs will be called an“owner”.

A body 104 of the robot 100 has a rounded form all over, and includes anouter skin formed of a soft material having elasticity, such asurethane, rubber, a resin, or a fiber. The robot 100 may be clothed. Bythe body 104, which is rounded, soft, and pleasant to touch, beingadopted, the robot 100 provides a user with a sense of security and apleasant tactile sensation.

A total weight of the robot 100 is 15 kilograms or less, preferably 10kilograms or less, and more preferably still 5 kilograms or less. Amajority of babies start to walk by themselves by 13 months after birth.An average weight of a baby 13 months after birth is a little over 9kilograms for boys, and a little under 9 kilograms for girls. Because ofthis, when the total weight of the robot 100 is 10 kilograms or less, auser can hold the robot 100 with an effort practically equivalent tothat of holding a baby that cannot walk by itself. An average weight ofa baby less than 2 months after birth is less than 5 kilograms for bothboys and girls. Consequently, when the total weight of the robot 100 is5 kilograms or less, a user can hold the robot 100 with an effortpractically equivalent to that of holding a very young baby.

Advantages of a user holding the robot 100 easily, and wanting to holdthe robot 100, are realized by the attributes of appropriate weight androundness, softness, and pleasantness of touch. For the same reasons, aheight of the robot 100 is desirably 1.2 meters or less, or preferably0.7 meters or less. Being able to be held is an important concept of therobot 100 in this embodiment.

The robot 100 includes three wheels for three-wheeled traveling. Asshown in the drawings, the robot 100 includes a pair of front wheels 102(a left wheel 102 a and a right wheel 102 b) and one rear wheel 103. Thefront wheels 102 are drive wheels, and the rear wheel 103 is a drivenwheel. Although the front wheels 102 have no steering mechanism,rotational speed and a direction of rotation can be individuallycontrolled. The rear wheel 103 is formed of a so-called omni wheel, androtates freely in order to cause the robot 100 to move forward and back,and left and right. By controlling so that the rotational speed of theright wheel 102 b is greater than that of the left wheel 102 a, therobot 100 can turn left or rotate counterclockwise. By controlling sothat the rotational speed of the left wheel 102 a is greater than thatof the right wheel 102 b, the robot 100 can turn right or rotateclockwise.

The front wheels 102 and the rear wheel 103 can be completely stored inthe body 104 using a drive mechanism (a pivoting mechanism and a linkingmechanism). A greater portion of each wheel is hidden by the body 104when traveling too, but when each wheel is completely stored in the body104, the robot 100 is in a state of being unable to move. That is, thebody 104 descends, and sits on a floor surface F, in accompaniment to anoperation of the wheels being housed. In the sitting state, a flatseating face 108 (a ground bottom face) formed in a bottom portion ofthe body 104 comes into contact with the floor surface F.

The robot 100 has two arms 106. The arms 106 do not have a function ofgripping an object. The arms 106 can perform simple actions such asraising, waving, and oscillating. The two arms 106 can also becontrolled individually.

A camera is incorporated in an eye 110. The eye 110 is also capable ofan image display using a liquid crystal element or an organic ELelement. In addition to the camera incorporated in the eye 110, varioussensors, such as a highly directional microphone and an ultrasonicsensor, are mounted in the robot 100. Also, a speaker is incorporated,and the robot 100 is also capable of simple speech.

A horn 112 is attached to a head portion of the robot 100. As the robot100 is lightweight, as heretofore described, a user can also lift up therobot 100 by grasping the horn 112.

A multiple of touch sensors 400 are installed along a curved bodysurface on the body 104 of the robot 100. The touch sensor 400 in thisembodiment is a projection type electrostatic capacitance sensor. Thetouch sensor 400 is such that a multiple of electrode wires areinstalled in a matrix form on a bendable plastic film. When a user comesinto contact with the planar touch sensor 400, electrostatic capacitancein a periphery of the place of contact changes. The place of contact(coordinates) is identified by electrode wires intersecting each otherin the touch sensor 400 detecting the change in electrostaticcapacitance. A multiple touch can also be detected in the case of theprojection type electrostatic capacitance method. Even when the touchsensor 400 and a finger do not come into direct contact, a touch througha glove, for example, can also be detected.

As shown in FIG. 1, the touch sensor 400 is installed over a whole ofthe body surface of the robot 100. The touch sensor 400 is installed onat least main portions such as the head portion, an abdomen portion, achest portion, a buttock portion, a lower back portion, the bottomportion, an upper back portion, and the arm 106 of the robot 100. “Mainportion” in this embodiment refers to at least both the head portion andthe abdomen portion (or the chest portion). Preferably, the upper backportion is also included. It is desirable that a touch on the upper backcan also be detected in addition to a touch on the head portion and theabdomen portion (or the chest portion). Providing the touch sensor 400on the bottom portion is useful for detecting a holding on a knee.Provided that contact with a main portion can be detected, the touchsensor 400 may be small in size.

Of course, the touch sensor 400 desirably covers the whole of the bodysurface of the robot 100. The touch sensor 400 desirably covers at least30% or more, preferably 50% or more, of the body surface.

The rounded, soft body 104 provides a user with a pleasant tactilesensation from the robot 100. Also, as the robot 100 incorporates heatgenerating parts such as a battery 118 and a control circuit 342 (to bedescribed hereafter), one portion of heat in the interior is transmittedto the body surface. Warmth of the body 104 of the robot 100 alsoincreases the pleasant sensation accompanying contact with the robot100.

FIG. 2 is a front external view of the robot 100 when wearing clothes.

A user can put clothing 180 on the robot 100. There are various kinds ofthe clothing 180. An RFID (radio frequency identifier) tag is sewn intothe clothing 180. The RFID tag emits “clothing ID” that identifiesclothing at close range. By reading the clothing ID from the RFID tag,the robot 100 can recognize that the robot 100 is wearing the clothing180, and recognize the category of the clothing 180 that the robot 100is wearing. The robot 100 may wear multiple items of the clothing 180 inlayers.

FIG. 3 is a sectional view schematically representing a structure of therobot 100.

As shown in FIG. 3, the body 104 of the robot 100 includes a base frame308, a main body frame 310, a pair of wheel covers 312 made of resin,and an outer skin 314. The base frame 308 is formed of metal, andsupports an internal mechanism together with configuring a shaft of thebody 104. The base frame 308 is configured by an upper plate 332 and alower plate 334 being linked vertically by a multiple of side plates336. A sufficient interval is provided between the multiple of sideplates 336 so that ventilation is possible. A battery 118, a controlcircuit 342, and various kinds of actuator are housed inside the baseframe 308.

The main body frame 310 is formed of a resin material, and includes ahead portion frame 316 and a trunk portion frame 318. The head portionframe 316 is of a hollow hemispherical form, and forms a head portionframework of the robot 100. The trunk portion frame 318 is of a steppedcylindrical form, and forms a trunk portion framework of the robot 100.The trunk portion frame 318 is integrally fixed to the base frame 308.The head portion frame 316 is attached to an upper end portion of thetrunk portion frame 318 so as to be relatively displaceable.

Three shafts, those being a yaw shaft 320, a pitch shaft 322, and a rollshaft 324, and an actuator 326 for driving each shaft so as to rotate,are provided in the head portion frame 316. The actuator 326 includes amultiple of servo motors for driving each shaft individually. The yawshaft 320 is driven for a head shaking action, the pitch shaft 322 isdriven for a nodding action, and the roll shaft 324 is driven for a headtilting action.

A plate 325 that supports the yaw shaft 320 is fixed to an upper portionof the head portion frame 316. A multiple of ventilation holes 327 forsecuring ventilation between upper and lower portions are formed in theplate 325.

A base plate 328 made of metal is provided so as to support the headportion frame 316 and an internal mechanism thereof from below. The baseplate 328 is linked to the plate 325 via a crosslink mechanism 329 (apantagraph mechanism), and is linked to the upper plate 332 (the baseframe 308) via a joint 330.

The trunk portion frame 318 houses the base frame 308 and a wheel drivemechanism 370. The wheel drive mechanism 370 includes a pivot shaft 378and an actuator 379. A lower half portion of the trunk portion frame 318is of a small width in order to form a housing space S of the frontwheel 102 between the wheel covers 312.

The outer skin 314 is formed of urethane rubber, and covers the mainbody frame 310 and the wheel covers 312 from an outer side. The arms 106are molded integrally with the outer skin 314. An aperture portion 390for introducing external air is provided in an upper end portion of theouter skin 314.

FIG. 4 is a configuration diagram of a robot system 300.

The robot system 300 includes the robot 100, the server 200, and amultiple of external sensors 114. The multiple of external sensors 114(external sensors 114 a, 1144 b, and so on to 114 n) are installed inadvance in a house. The external sensor 114 may be fixed to a wallsurface of the house, or may be placed on a floor. Positionalcoordinates of the external sensor 114 are registered in the server 200.The positional coordinates are defined as x, y coordinates in the houseenvisaged to be an action range of the robot 100.

The server 200 is installed in the house. The server 200 and the robot100 in this embodiment correspond one-to-one. The server 200 determinesa basic action of the robot 100 based on information obtained from thesensors incorporated in the robot 100 and the multiple of externalsensors 114.

The external sensor 114 is for reinforcing sensory organs of the robot100, and the server 200 is for reinforcing brainpower of the robot 100.

The external sensor 114 regularly transmits a wireless signal (hereaftercalled a “robot search signal”) including ID (hereafter called “beaconID”) of the external sensor 114. On receiving the robot search signal,the robot 100 returns a wireless signal (hereafter called a “robotresponse signal”) including beacon ID. The server 200 measures a timefrom the external sensor 114 transmitting the robot search signal untilreceiving the robot response signal, and measures a distance from theexternal sensor 114 to the robot 100. By measuring the distance betweeneach of the multiple of external sensors 114 and the robot 100, theserver 200 identifies the positional coordinates of the robot 100.

Of course, a method whereby the robot 100 regularly transmits its ownpositional coordinates to the server 200 may also be adopted.

FIG. 5 is a schematic view of an emotion map 116.

The emotion map 116 is a data table stored in the server 200. The robot100 selects an action in accordance with the emotion map 116. Theemotion map 116 shown in FIG. 5 shows a magnitude of an emotionalattachment or aversion to a place of the robot 100. An x axis and a yaxis of the emotion map 116 indicate two-dimensional spatialcoordinates. A z axis indicates a magnitude of an emotional attachmentor aversion. When a z value is a positive value, an attachment to theplace is high, and when the z value is a negative value, the robot 100is averse to the place.

On the emotion map 116 of FIG. 5, a coordinate P1 is a point in anindoor space managed by the server 200 as the action range of the robot100 at which an emotion of attraction is high (hereafter called afavored point). The favored point may be a “safe place”, such as behinda sofa or under a table, or may be a place in which people tend togather or a lively place, like a living room. Also, the safe place maybe a place where the robot 100 has been gently stroked or touched in thepast.

A definition of what kind of place the robot 100 favors is arbitrary,but it is generally desirable that a place favored by small children, orby small animals such as dogs or cats, is set as a favored point.

A coordinate P2 is a point at which an emotion of aversion is high(hereafter called a “disliked point”). The disliked point may be a placewhere there is a loud noise, such as near a television, a place wherethere is likely to be a leak, like a bathroom or a washroom, an enclosedspace or a dark place, a place where the robot 100 has been roughlytreated by a user and that invokes an unpleasant memory, or the like.

A definition of what kind of place the robot 100 dislikes is alsoarbitrary, but it is generally desirable that a place feared by smallchildren, or by small animals such as dogs or cats, is set as a dislikedpoint.

A coordinate Q indicates a current position of the robot 100. The server200 identifies positional coordinates of the robot 100, using the robotsearch signal regularly transmitted by the multiple of external sensors114 and the robot response signal responding to the robot search signal.For example, when the external sensor 114 with beacon ID=1 and theexternal sensor 114 with beacon ID=2 each detect the robot 100, theserver 200 obtains the distances of the robot 100 from the two externalsensors 114, and obtains the positional coordinates of the robot 100from the distances.

Alternatively, the external sensor 114 with beacon ID=1 transmits therobot search signal in a multiple of directions, and the robot 100returns the robot response signal when receiving the robot searchsignal. By so doing, the server 200 may ascertain in which direction,and at what distance, the robot 100 is from which external sensor 114.Also, in another embodiment, the server 200 may calculate a distancemoved by the robot 100 from the rotational speed of the front wheel 102or the rear wheel 103, thereby identifying the current position, or mayidentify the current position based on an image obtained from thecamera.

When the emotion map 116 shown in FIG. 5 is provided, the robot 100moves in a direction toward the favored point (coordinate P1), or in adirection away from the disliked point (coordinate P2).

The emotion map 116 changes dynamically. When the robot 100 arrives atthe coordinate P1, the z value (emotion of attraction) at the coordinateP1 decreases with the passing of time. Because of this, the robot 100can emulate animal-like behavior of arriving at the favored point(coordinate P1), “being emotionally satisfied”, and in time “gettingbored” with the place. In the same way, the emotion of aversion at thecoordinate P2 is alleviated with the passing of time. A new favoredpoint or disliked point appears together with the elapse of time,because of which the robot 100 carries out a new action selection. Therobot 100 has “interest” in a new favored point, and ceaselessly carriesout a new action selection.

The emotion map 116 expresses emotional swings as an internal state ofthe robot 100. The robot 100 heads for a favored point, avoids adisliked point, stays for a while at the favored point, and in timeperforms the next action. With this kind of control, the actionselection of the robot 100 can be a human-like or animal-like actionselection.

Maps that affect an action of the robot 100 (hereafter collectivelycalled “action maps”) are not limited to the type of emotion map 116shown in FIG. 5. For example, various action maps such as curiosity, adesire to avoid fear, a desire to seek security, and a desire to seekphysical ease such as quietude, low light, coolness, or warmth, can bedefined. Further, an objective point of the robot 100 may be determinedby taking a weighted average of the z values of each of a multiple ofaction maps.

The robot 100 may also have, in addition to an action map, parametersthat indicate a magnitude of various emotions or senses. For example,when a value of a loneliness emotion parameter is increasing, aweighting coefficient of an action map that evaluates places in whichthe robot 100 feels at ease may be set high, and the value of thisemotion parameter reduced by the robot 100 reaching a target point. Inthe same way, when a value of a parameter indicating a sense of boredomis increasing, it is sufficient that a weighting coefficient of anaction map that evaluates places in which curiosity is satisfied is sethigh.

FIG. 6 is a hardware configuration diagram of the robot 100.

The robot 100 includes an internal sensor 128, a communicator 126, astorage device 124, a processor 122, a drive mechanism 120, and thebattery 118. The drive mechanism 120 includes the heretofore describedwheel drive mechanism 370. The processor 122 and the storage device 124are included in the control circuit 342. The units are connected to eachother by a power line 130 and a signal line 132. The battery 118supplies power to each unit via the power line 130. Each unit transmitsand receives a control signal via the signal line 132. The battery 118is a lithium ion rechargeable battery, and is a power source of therobot 100.

The internal sensor 128 is a collection of various kinds of sensorincorporated in the robot 100. Specifically, the internal sensor 128 isa camera, a highly directional microphone, an infrared sensor, athermosensor, a touch sensor, an acceleration sensor, a smell sensor,and the like. The smell sensor is an already known sensor that applies aprinciple that electrical resistance changes in accordance with anadsorption of a molecule forming a source of a smell. The smell sensorclassifies various smells into multiple kinds of category (hereaftercalled “smell categories”).

The communicator 126 is a communication module that carries out wirelesscommunication with the server 200 and various kinds of external device,such as the external sensor 114 and a mobile device possessed by a user,as a target. The storage device 124 is configured of a non-volatilememory and a volatile memory, and stores a computer program and variouskinds of setting information. The processor 122 is means of executing acomputer program. The drive mechanism 120 is an actuator that controlsan internal mechanism. In addition to this, an indicator, a speaker, andthe like are also mounted.

The processor 122 selects an action of the robot 100 while communicatingwith the server 200 or the external sensor 114 via the communicator 126.Various kinds of external information obtained by the internal sensor128 also affect the action selection. The drive mechanism 120 mainlycontrols the wheels (front wheels 102) and the head portion (the headportion frame 316). The drive mechanism 120 changes a direction ofmovement and a movement speed of the robot 100 by changing therotational speed and the direction of rotation of each of the two frontwheels 102. Also, the drive mechanism 120 can also raise and lower thewheels (the front wheels 102 and the rear wheel 103). When the wheelsrise, the wheels are completely stored in the body 104, and the robot100 comes into contact with the floor surface F via the seating face108, taking on the sitting state.

FIG. 7 is a functional block diagram of the robot system 300.

As heretofore described, the robot system 300 includes the robot 100,the server 200, and the multiple of external sensors 114. Each componentof the robot 100 and the server 200 is realized by hardware including acomputer formed of a CPU (central processing unit), various kinds ofcoprocessor, and the like, a storage device that is a memory or storage,and a wired or wireless communication line that links the computer andthe storage device, and software that is stored in the storage deviceand supplies a processing command to the computer. A computer programmay be configured of a device driver, an operating system, various kindsof application program positioned in an upper layer thereof, and alibrary that provides a common function to the programs. Each blockdescribed hereafter indicates a functional unit block rather than ahardware unit configuration.

One portion of the functions of the robot 100 may be realized by theserver 200, and one portion or all of the functions of the server 200may be realized by the robot 100.

Server 200

The server 200 includes a communication unit 204, a data processing unit202, and a data storage unit 206.

The communication unit 204 manages a process of communicating with theexternal sensor 114 and the robot 100. The data storage unit 206 storesvarious kinds of data. The data processing unit 202 executes variouskinds of process based on data acquired by the communication unit 204and data stored in the data storage unit 206. The data processing unit202 also functions as an interface of the communication unit 204 and thedata storage unit 206.

The data storage unit 206 includes a motion storage unit 232, a mapstorage unit 216, and an individual data storage unit 218.

The robot 100 has a multiple of operation patterns (motions). Variousmotions, such as waving a hand, approaching a user while meandering, andstaring at a user with the head to one side, are defined.

The motion storage unit 232 stores a “motion file” that defines controldetails of a motion. Each motion is identified by motion ID. The motionfile is also downloaded into a motion storage unit 160 of the robot 100.Which motion is to be executed may be determined by the server 200, ormay be determined by the robot 100.

Many motions of the robot 100 are configured as compound motions thatinclude a multiple of unit motions. For example, when the robot 100approaches an owner, the approach may be expressed as a combination of aunit motion of changing direction to face the owner, a unit motion ofapproaching while raising an arm, a unit motion of approaching whileshaking the body, and a unit motion of sitting while raising both arms.By combining these kinds of four motions, a motion of “approaching anowner, raising one arm on the way, and finally sitting after shaking thebody” is realized. An angle of rotation, angular velocity, and the likeof an actuator provided in the robot 100 is defined correlated to a timeaxis in a motion file. Various motions are performed by each actuatorbeing controlled together with the passing of time in accordance withthe motion file (actuator control information).

A shift time for changing from a preceding unit motion to a subsequentunit motion is called an “interval”. It is sufficient that an intervalis defined in accordance with time needed for a unit motion change ordetails of a motion. A length of an interval can be regulated.

Hereafter, settings involved in controlling an action of the robot 100,such as which motion is chosen and when, and output regulation of eachactuator when realizing a motion, will collectively be called“behavioral characteristics”. The behavioral characteristics of therobot 100 are defined by a motion selection algorithm, a selectionprobability of a motion chosen in response to various situations, amotion file, and the like.

The map storage unit 216 stores a multiple of act ion maps. Theindividual data storage unit 218 stores information on a user, and inparticular, on an owner. Specifically, the individual data storage unit218 stores various kinds of parameter, such as familiarity with respectto a user, and physical characteristics and behavioral characteristicsof a user. The individual data storage unit 218 may also store otherattribute information such as age and gender.

The robot 100 identifies a user based on the user's physicalcharacteristics or behavioral characteristics. The robot 100 constantlyfilms a periphery using the incorporated camera. Further, the robot 100extracts the physical characteristics and behavioral characteristics ofa person appearing in an image. The physical characteristics may bevisual characteristics inherent to a body, such as a height, clothesworn by choice, a presence or absence of spectacles, a skin color, ahair color, or an ear size, or may also include other characteristicssuch as an average body temperature, a smell, and a voice quality. Thebehavioral characteristics, specifically, are characteristicsaccompanying behavior, such as a place the user favors, a briskness ofmovement, and a presence or absence of smoking. For example, the robot100 extracts behavioral characteristics such that an owner identified asa father is often out of the home, and is often motionless on a sofawhen at home, but a mother is often in a kitchen, and an activity rangeis broad.

The robot 100 clusters users appearing with a high frequency as “owners”based on physical characteristics and behavioral characteristicsobtained from a large amount of image information or other sensinginformation.

Although the method of identifying a user from user ID is simple andreliable, the user having a device that can provide user ID is aprecondition. Meanwhile, the method of identifying a user from physicalcharacteristics or behavioral characteristics is such that an imagerecognition process is weighty, but there is an advantage in that even auser who does not have a mobile device can be identified. One of the twomethods may be employed alone, or user identification may be carried outusing the two methods together in a complementary way.

In this embodiment, users are clustered based on physicalcharacteristics and behavioral characteristics, and a user is identifiedusing deep learning (a multilayer neural network). Details will bedescribed hereafter.

The robot 100 has a familiarity internal parameter for each user. Whenthe robot 100 recognizes an action indicating a liking toward the robot100, such as picking the robot 100 up or speaking to the robot 100,familiarity with respect to that user increases. Familiarity decreaseswith respect to a user not involved with the robot 100, a user whobehaves roughly, or a user met infrequently.

The data processing unit 202 includes a position managing unit 208, amap managing unit 210, a recognizing unit 212, an operation control unit222, and a familiarity managing unit 220.

The position managing unit 208 identifies the positional coordinates ofthe robot 100 using the method described using FIG. 4. The positionmanaging unit 208 may also track positional coordinates of a user inreal time.

The map managing unit 210 changes the parameter of each coordinate onthe multiple of action maps using the method described in connectionwith FIG. 5. The map managing unit 210 may select one of the multiple ofaction maps, or may take a weighted average of the z values of themultiple of action maps. For example, it is taken that the z values at acoordinate R1 and a coordinate R2 on an action map A are 4 and 3, andthe z values at the coordinate R1 and the coordinate R2 on an action mapB are −1 and 3. When taking a simple average, the total z value at thecoordinate R1 is 4−1=3, and the total z value at the coordinate R2 is3+3=6, because of which the robot 100 heads in the direction of thecoordinate R2 rather than the coordinate R1.

When the action map A is weighted 5 times with respect to the action mapB, the total z value at the coordinate R1 is 4×5−1=19, and the total zvalue at the coordinate R2 is 3×5+3=18, because of which the robot 100heads in the direction of the coordinate R1.

The recognizing unit 212 recognizes an external environment. Variouskinds of recognition, such as recognition of weather or season based ontemperature and humidity, and recognition of shelter (a safe area) basedon an amount of light and temperature, are included in the recognitionof the external environment. The recognizing unit 212 further includes aperson recognizing unit 214 and a response recognizing unit 228. Theperson recognizing unit 214 recognizes a person from an image filmed bythe camera incorporated in the robot 100, and extracts the physicalcharacteristics and behavioral characteristics of the person. Further,based on the physical characteristic information and behavioralcharacteristic information registered in the individual data storageunit 218, the person recognizing unit 214 determines what person, suchas a father, a mother, or an eldest son, the user filmed, that is, theuser the robot 100 is looking at, corresponds to. The person recognizingunit 214 includes an expression recognizing unit 230. The expressionrecognizing unit 230 estimates an emotion of a user using imagerecognition of an expression of the user.

The person recognizing unit 214 also extracts characteristics of amoving object other than a person, for example, a cat or a dog that is apet.

The response recognizing unit 228 recognizes various responsive actionsperformed by a user with respect to the robot 100, and classifies theactions as pleasant or unpleasant actions. The response recognizing unit228 includes an emotion estimating unit 250. The emotion estimating unit250 estimates an emotion of a user based on physical contact by the userwith the robot 100, and identifies an affection expression level. Theaffection expression level is a parameter wherein an emotion of a usertoward the robot 100 is estimated (to be described hereafter).

Pleasant and unpleasant actions are distinguished depending on whether aresponsive action of a user is pleasant or unpleasant for a livingcreature. For example, being hugged is a pleasant action for the robot100, and being kicked is an unpleasant action for the robot 100. It isdetermined that a possibility of a user who performs a pleasant actionhaving a positive emotion is high, and a possibility of a user whoperforms an unpleasant action having a negative emotion is high.

The operation determining unit 222 of the server 200 determines a motionof the robot 100 in cooperation with an operation control unit 150 ofthe robot 100. The operation determining unit 222 of the server 200compiles a movement target point of the robot 100, and a movement routefor the movement target point, based on an action map selection by themap managing unit 210. The operation determining unit 222 compiles amultiple of movement routes, and having done so, may select any of themovement routes.

The operation control unit 222 selects a motion of the robot 100 from amultiple of motions of the motion storage unit 232. A selectionprobability is correlated for each situation to each motion. Forexample, a selection method such that a motion A is executed with aprobability of 20% when a pleasant action is performed by a user, and amotion B is executed with a probability of 5% when an air temperature is30° C. or higher, is defined.

A movement target point and a movement route are determined by an actionmap, and a motion is selected in accordance with various kinds of eventto be described hereafter.

The familiarity managing unit 220 manages familiarity for each user. Asheretofore described, familiarity is registered as one portion ofindividual data in the individual data storage unit 218. When a pleasantaction is detected, the familiarity managing unit 220 increasesfamiliarity with respect to that user. When an unpleasant action isdetected, the familiarity managing unit 220 reduces familiarity. Also,familiarity of an owner who has not been visually recognized for a longperiod gradually decreases.

Robot 100

The robot 100 includes a communication unit 142, a data processing unit136, a data storage unit 148, the internal sensor 128, and the drivemechanism 120.

The communication unit 142 corresponds to the communicator 126 (refer toFIG. 6), and manages a process of communicating with the external sensor114 and the server 200. The data storage unit 148 stores various kindsof data. The data storage unit 148 corresponds to the storage device 124(refer to FIG. 6). The data processing unit 136 executes various kindsof process based on data acquired by the communication unit 142 and datastored in the data storage unit 148. The data processing unit 136corresponds to the processor 122 and a computer program executed by theprocessor 122. The data processing unit 136 also functions as aninterface of the communication unit 142, the internal sensor 128, thedrive mechanism 120, and the data storage unit 148.

The internal sensor 128 includes the touch sensor 400, a camera 402, anda thermosensor 404.

The touch sensor 400 detects contact by a user on the body 104. Thecamera 402 constantly films a periphery of the robot 100. Thethermosensor 404 regularly detects an external air temperaturedistribution in the periphery of the robot 100. By a predeterminedprocessing such as an image processing being performed on informationobtained from the camera 402 and the thermosensor 404, whether or not auser exists in the periphery can be detected.

The data storage unit 148 includes the motion storage unit 160, whichdefines various kinds of motion of the robot 100.

Various kinds of motion file are downloaded from the motion storage unit232 of the server 200 into the motion storage unit 160 of the robot 100.A motion is identified by motion ID. An operating timing, an operatingtime, an operating direction, and the like, of the various kinds ofactuator (the drive mechanism 120) are defined chronologically in orderto perform various motions such as sitting by housing the front wheel102, raising the arm 106, causing the robot 100 to carry out a rotatingaction by causing the two front wheels 102 to rotate in reverse or bycausing only one front wheel 102 to rotate, shaking by causing the frontwheel 102 to rotate in a state in which the front wheel 102 is housed,or stopping once and looking back when moving away from a user.

The data processing unit 136 includes a recognizing unit 156, theoperation control unit 150, a clothing detecting unit 172, and asensitivity control unit 174.

The operation control unit 150 of the robot 100 determines motions ofthe robot 100 in cooperation with the operation control unit 222 of theserver 200. One portion of motions may be determined by the server 200,and other motions may be determined by the robot 100. Also, aconfiguration may be such that although the robot 100 determinesmotions, the server 200 determines a motion when a processing load ofthe robot 100 is high. A configuration may be such that a motion forminga base is determined by the server 200, and an additional motion isdetermined by the robot 100. It is sufficient that the way a motiondetermining process is divided between the server 200 and the robot 100is designed in accordance with specifications of the robot system 300.

The operation control unit 150 of the robot 100 determines a directionof movement of the robot 100 together with the operation control unit222 of the server 200. Movement based on an action map may be determinedby the server 200, and an immediate movement such as avoiding anobstacle may be determined by the operation control unit 150 of therobot 100. The drive mechanism 120 causes the robot 100 to head toward amovement target point by driving the front wheel 102 in accordance withan instruction from the operation control unit 150.

The operation control unit 150 of the robot 100 instructs the drivemechanism 120 to execute a selected motion. The drive mechanism 120controls each actuator in accordance with the motion file.

The operation control unit 150 can also execute a motion of holding upboth arms 106 as a gesture asking for “a hug” when a user with a highdegree of familiarity is nearby, and can also perform a motion of nolonger wanting to be hugged by alternately and repeatedly causing theright and left front wheels 102 to rotate in reverse and stop in ahoused state when bored of the “hug”. The drive mechanism 120 causes therobot 100 to perform various motions by driving the front wheels 102,the arm 106, and the neck (the head unit frame 316) in accordance withan instruction from the operation control unit 150.

When a responsive action indicating a strong expression of affection,for example, physical contact such as hugging the robot 100 tight, isdetected, the operation control unit 150 selects a predetermined motionsuch as further entrusting the body to the user, and rubbing the faceagainst the user.

The sensitivity control unit 174 causes sensitivity, specificallydetection voltage, of the touch sensor 400 to change. This will bedescribed in detail hereafter.

The clothing detecting unit 172 detects a wearing of the clothing 180 bydetecting the clothing ID from the RFID tag of the clothing 180. Theclothing ID can be read when within close range. When multiple items ofclothing ID are read, it is determined that the robot 100 is wearingclothing in layers. A wearing of clothing may be detected using variousmethods other than the RFID tag. For example, it may be determined thatclothing has been put on when an internal temperature of the robot 100rises. Clothing worn may be recognized from an image using the camera.When the touch sensor 400 detects contact over a wide range, it may bedetermined that clothing has been put on.

The recognizing unit 156 of the robot 100 analyzes external informationobtained from the internal sensor 128. The recognizing unit 156 iscapable of visual recognition (a visual unit), smell recognition (anolfactory unit), sound recognition (an aural unit), and tactilerecognition (a tactile unit).

The recognizing unit 156 regularly films an exterior angle using theincorporated camera (the internal sensor 128), and detects a movingobject such as a person or a pet. The recognizing unit 156 carries outan extraction of characteristics from an image or the like. Thecharacteristics are transmitted to the server 200, and the personrecognizing unit 214 of the server 200 extracts the physicalcharacteristics of the moving object. Also, the recognizing unit 156also detects a smell of the user and a voice of the user. Smell andsound (voice) are classified into multiple kinds using an already knownmethod.

When a strong force is applied to the robot 100, the recognizing unit156 recognizes this using an incorporated acceleration sensor, and theresponse recognizing unit 228 of the server 200 recognizes that a“violent action” has been performed by a user in the vicinity. When auser picks the robot 100 up by grabbing the horn 112, this may also berecognized as a violent action. When a user in a state of confrontingthe robot 100 speaks in a specific volume region and a specificfrequency band, the response recognizing unit 228 of the server 200 mayrecognize that a “speaking action” has been performed with respect tothe robot 100. Also, when a temperature in the region of bodytemperature is detected, the response recognizing unit 228 of the server200 recognizes that a “touching action” has been performed by a user,and when upward acceleration is detected in a state in which touching isrecognized, the response recognizing unit 228 of the server 200recognizes that a “hug” has been performed. Physical contact when a userraises the body 104 may also be sensed, and a hug may also be recognizedby a load acting on the front wheels 102 decreasing.

The affection expression level is identified in accordance with detailsof a responsive action, specifically, an aspect of physical contact.Various aspects, such as hugging tight, rubbing cheeks, and stroking thehead, exist as physical contact. Hereafter, an aspect of physicalcontact is referred to as a “contact aspect”. In general, almost allresponsive actions that are pleasant actions are of a high affectionexpression level, and almost all responsive actions that are unpleasantactions are of a low affection expression level. Pleasant and unpleasantactions are related to familiarity, and the affection expression levelaffects the action selection of the robot 100.

A series of recognition processes may be carried out by the recognizingunit 212 of the server 200 alone, or carried out by the recognizing unit156 of the robot 100 alone, or the two may execute the recognitionprocesses while dividing roles.

The familiarity managing unit 220 of the server 200 changes thefamiliarity toward a user in accordance with a responsive actionrecognized by the recognizing unit 156. Essentially, the familiaritytoward a user who carries out a pleasant action increases, while thefamiliarity toward a user who carries out an unpleasant actiondecreases.

The recognizing unit 212 of the server 200 may determine whether aresponse is pleasant or unpleasant, and the map managing unit 210 of theserver 200 may change the z value of the point at which the pleasant orunpleasant action has been carried out on an action map that represents“attachment to a place”. For example, when a pleasant action is carriedout in a living room, the map managing unit 210 may set a favored pointat a high probability in the living room. In this case, a positivefeedback advantage is realized in that the robot 100 favors the livingroom, and further favors the living room due to being the recipient of apleasant action in the living room.

The person recognizing unit 214 of the server 200 detects a movingobject from various kinds of data obtained from the external sensor 114or the internal sensor 128, and extracts characteristics (physicalcharacteristics and behavioral characteristics) thereof. Further, theperson recognizing unit 214 cluster analyzes multiple moving objectsbased on these characteristics. Not only a human, but also a pet such asa dog or cat, may be a target of analysis as a moving object.

The robot 100 regularly carries out image filming, and the personrecognizing unit 214 recognizes a moving object from the images, andextracts characteristics of the moving object. When a moving object isdetected, physical characteristics and behavioral characteristics arealso extracted from the smell sensor, the incorporated highlydirectional microphone, the temperature sensor, and the like. Forexample, when a moving object appears in an image, variouscharacteristics are extracted, such as having a beard, being activeearly in the morning, wearing red clothing, smelling of perfume, havinga loud voice, wearing spectacles, wearing a skirt, having white hair,being tall, being plump, being suntanned, or being on a sofa.

When a moving object (user) having a beard is often active early in themorning (gets up early) and rarely wears red clothing, a first profilethat is a cluster (user) that gets up early, has a beard, and does notoften wear red clothing is created. Meanwhile, when a moving objectwearing spectacles often wears a skirt, but the moving object does nothave a beard, a second profile that is a cluster (user) that wearsspectacles and wears a skirt, but definitely does not have a beard, iscreated.

Although the above is a simple example, the first profile correspondingto a father and the second profile corresponding to a mother are formedusing the heretofore described method, and the robot 100 recognizes thatthere at least two users (owners) in this house.

Note that the robot 100 does not need to recognize that the firstprofile is the “father”. In all cases, it is sufficient that the robot100 can recognize a figure that is “a cluster that has a beard, oftengets up early, and hardly ever wears red clothing”.

It is assumed that the robot 100 newly recognizes a moving object (user)in a state in which this kind of cluster analysis is completed.

At this time, the person recognizing unit 214 of the server 200 extractscharacteristics from sensing information of an image or the likeobtained from the robot 100, and determines which cluster a movingobject near the robot 100 corresponds to using deep learning (amultilayer neural network). For example, when a moving object that has abeard is detected, the probability of the moving object being the fatheris high. When the moving object is active early in the morning, it isstill more certain that the moving object corresponds to the father.Meanwhile, when a moving object that wears spectacles is detected, thereis a possibility of the moving object being the mother. When the movingobject has a beard, the moving object is neither the mother nor thefather, because of which the person recognizing unit 214 determines thatthe moving object is a new person who has not been cluster analyzed.

Formation of a cluster by characteristic extraction (cluster analysis)and application to a cluster accompanying characteristic extraction(deep learning) may be executed concurrently.

Familiarity toward a moving object (user) changes in accordance with howthe robot 100 is treated by the user.

The robot 100 sets a high familiarity for a frequently met person, aperson who frequently touches the robot 100, and a person who frequentlyspeaks to the robot 100. Meanwhile, familiarity decreases for a rarelyseen person, a person who does not often touch the robot 100, a violentperson, and a person who scolds in a loud voice. The robot 100 changesthe familiarity of each user based on various items of exterior angleinformation detected by the sensors (visual, tactile, and aural).

The actual robot 100 autonomously carries out a complex action selectionin accordance with an action map. The robot 100 acts while beingaffected by a multiple of action maps based on various parameters suchas loneliness, boredom, and curiosity. When the effect of the actionmaps is removed, or when in an internal state in which the effect of theaction maps is small, the robot 100 essentially attempts to approach aperson with high familiarity, and attempts to move away from a personwith low familiarity.

Actions of the robot 100 are classified below in accordance withfamiliarity.

(1) A cluster with extremely high familiarity

The robot 100 strongly expresses a feeling of affection by approaching auser (hereafter called “an approaching action”), and by performing anaffectionate gesture defined in advance as a gesture indicating goodwilltoward a person.

(2) A cluster with comparatively high familiarity

The robot 100 carries out only an approaching action.

(3) A cluster with comparatively low familiarity

The robot 100 does not carry out any special action.

(4) A cluster with particularly low familiarity

The robot 100 carries out a withdrawing action.

According to the heretofore described control method, the robot 100approaches the user when finding a user with high familiarity, andconversely, moves away from the user when finding a user with lowfamiliarity. According to this kind of control method, the robot 100 canexpress by behavior a so-called “shyness”. Also, when a visitor (a userA with low familiarity) appears, the robot 100 may move away from thevisitor and head toward a family member (a user B with highfamiliarity). In this case, user B can perceive that the robot 100 isshy and feeling uneasy, and relying on user B. Owing to this kind ofbehavioral expression, pleasure at being chosen and relied upon, and anaccompanying feeling of affection, are evoked in user B.

Meanwhile, when user A, who is a visitor, visits frequently, and speaksto and touches the robot 100, familiarity of the robot 100 toward user Agradually rises, and the robot 100 ceases to perform an action ofshyness (a withdrawing action) with respect to user A. User A can alsofeel affection toward the robot 100 by perceiving that the robot 100 hasbecome accustomed to user A.

The heretofore described action selection need not necessarily beexecuted constantly. For example, when an internal parameter indicatingcuriosity of the robot 100 is high, weight is given to an action mapfrom which a place in which the curiosity is satisfied is obtained,because of which there is also a possibility that the robot 100 does notselect an action affected by familiarity. Also, when the external sensor114 installed in the hall detects the return home of a user, the robot100 may execute an action of greeting the user with maximum priority.

When sensing by a sensor other than the touch sensor 400, for example,the camera 402, the thermosensor 404, an unshown smell sensor, or thelike, is impeded by contact from a user, the operation control unit 150executes a notification operation. Specifically, when a certain ratio ormore, for example 50% or more, of a field of view of the camera 402 isblocked, or when a certain ratio or more of a detection range of thethermosensor 404 is detected as being of the same temperaturedistribution, there is a possibility that a user's hand or body isimpeding sensing. When it is determined by the recognizing unit 156 thata period for which sensing is impeded has continued for a predeterminedtime or longer, the operation control unit 150 executes a notificationoperation.

A notification operation is an operation of reporting to an owner thematter that there is a user or an obstacle, and that a sensor other thanthe touch sensor 400 cannot carry out sensing normally. Specifically,the operation control unit 150 executes a notification operation such ascausing the eye to light up, emitting speech, shaking the body, orattempting to run away. It is sufficient that the notification operationis initially set in advance as a “typical operation (motion) whennotifying of something” peculiar to the robot 100.

FIG. 8 is a sectional enlarged view of the body 104.

A second layer touch sensor 400 b is sandwiched between the main bodyframe 310 and the outer skin 314. The second layer touch sensor 400 b isinstalled along a curved form of the main body frame 310, which is madeof resin. The outer skin 314 is made of urethane rubber (an elasticbody). A covering skin 406 made of cloth is affixed to a surface of theouter skin 314, and a first layer touch sensor 400 a is also installedalong a curved form of the outer skin 314 between the outer skin 314 andthe covering skin 406. That is, two touch sensors 400 form a doublelayer. The soft outer skin 314 is also a place a user feels a desire totouch. By the touch sensor 400 being disposed in a portion covered bythe outer skin 314, a large variety of contacts from a user can beeffectively detected.

The first touch sensor 400 a may be installed on the covering skin 406.

When a user touches the covering skin 406, the first layer touch sensor400 a detects the contact. When a user presses the covering skin 406hard, not only the first layer touch sensor 400 a but also the secondlayer touch sensor 400 b detects the contact. That is, strength ofcontact can be determined by the two touch sensors 400 of differingdepths. Generally, an electrostatic capacitance sensor is such that thesmaller the distance between an object and the sensor, the greater adetected value becomes. When a user touches the body 104 hard, the outerskin 314 transforms, and a distance between skin of the user and thesecond layer touch sensor 400 b decreases, because of which the valuedetected by the second layer touch sensor 400 b changes. As the outerskin 314 does not transform unless a certain amount of force is applied,whether the robot 100 is being hugged tightly or being hugged gently canbe detected by the second layer touch sensor 400 b, which is in a deepportion.

Various contact aspects can be classified by a combination of contactplace, contact strength, and contact time. When only the first layertouch sensor 400 a detects a contact, the recognizing unit 156recognizes the contact as a “light touch”. When the first layer touchsensor 400 a detects an intermittent contact, the recognizing unit 156recognizes the contact as “being poked”. When not only the first layertouch sensor 400 a but also the second layer touch sensor 400 b detectsa contact continuously for a certain time, the recognizing unit 156recognizes the contact as a “massage”. When the first layer touch sensor400 a and the second layer touch sensor 400 b simultaneously detect amomentary contact, the recognizing unit 156 recognizes the contact as“being hit”. The recognizing unit 156 may recognize a “violent action”in combination with the incorporated acceleration sensor.

As the touch sensor 400 is provided over the whole of the robot 100,what kind of contact is being carried out can be comprehensivelydetermined from a combination of contact places. For example, when auser lifts the robot 100 up with a hand on either side, contact isdetected on both side portions of the trunk. Being lifted up can also bedetected by the incorporated acceleration sensor. When a user places therobot 100 on a knee and has both hands on the trunk of the robot 100,contact is detected in the bottom portion and the trunk portion. At thistime, contact on the trunk portion is not normally strong. According tothis kind of contact aspect, a holding on a knee can be recognized. Whenhugging the robot 100 tightly from in front, contact is detected over awide region such as the chest, the abdomen, the upper back, and the headportion, and the contact is strong.

Identification information for identifying the contact aspect (hereafterreferred to as “contact aspect ID”) is allotted to each contact aspect.The emotion estimating unit 250 identifies the contact aspect ID basedon the combination of contact places and the contact strength. Forexample, the emotion estimating unit 250 may hold a table in which acombination of contact places and the contact aspect ID are correlatedin advance, and identify the contact aspect ID by referring to thetable. Also, a program module for determination may be prepared for eachcontact aspect, and a contact aspect may be identified by each modulecarrying out a predetermined determination process based on a signalfrom the touch sensor 400 or the internal sensor 128. Contact aspect IDis correlated to motion data held in the motion storage unit 232. Theoperation control unit 222 selects the motion correlated to the contactaspect ID. That is, by a motion being correlated in advance to eachaspect of physical contact, the operation control unit 222 can select amotion that responds appropriately to an emotion of a user who hasperformed physical contact.

In another form, a configuration may be such that information indicatingan emotion of the robot is correlated to motion data held in the motionstorage unit 232, and the operation control unit 222 can select a motionin accordance with an emotion of the robot 100. That is, when theemotion of the robot 100 is one of “wanting to be indulged”, a motioncorrelated to the emotion of wanting to be indulged is selected. Anemotion of a user is integrated in each aspect of physical contact. Theemotion estimating unit 250 holds information correlated to contactaspect ID and indicating an emotion of a user. Because of this, therobot 100 recognizes an aspect of physical contact received from a user,and can estimate the emotion of the user from the aspect. For example,information indicating an emotion of “you're cute” may be correlated toa contact aspect of “stroking the head”.

The operation control unit 222 causes an emotion of the robot 100 itselfto change in accordance with an emotion of a user estimated by theemotion estimating unit 250, and selects a motion in accordance with theemotion of the robot 100. The operation control unit 222 holds anemotion of the robot 100 itself with respect to an emotion of a user,correlated to the emotion of the user. For example, the emotion of“wanting to be indulged” is correlated as the emotion of the robot withrespect to the emotion of a user of “you're cute”. Because of this, theoperation control unit 222 can determine an emotion of the robot 100itself in accordance with an emotion of a user. Further, the operationcontrol unit 222 retrieves motion data corresponding to an emotion ofthe robot 100 itself from the motion storage unit 232, and executes amotion. For example, the operation control unit 222 selects motion datacorrelated to the emotion of “wanting to be indulged”. A multiple ofemotions may be correlated as emotions of the robot 100 with respect toan emotion of a user, and one emotion is selected in accordance withfamiliarity toward the user, or the like.

By the touch sensor 400 being provided over practically the whole of therobot 100, how the robot 100 is touched by a user can be determined, andthe current contact aspect can be identified from among the multiple ofcontact aspects. Although physical contact has various aspects, it isknown that each contact aspect has a psychological meaning. This meansthat provided the contact aspect is known, an emotion of a user withrespect to the robot 100 can be estimated. Further, by the robot 100operating so as to respond appropriately to the estimated emotion of theuser, the user feels pleasure, and has an emotion equivalent with thattoward a living pet.

Also, the emotion estimating unit 250 determines an affection expressionlevel in accordance with a contact aspect. A data table in which acontact aspect and an affection expression level that forms a base arecorrelated, as in an affection expression level of a simple touch being“+1” and an affection expression level of a hug being “+10”, isprepared. The emotion estimating unit 250 identifies the affectionexpression level based on the data table. When a light touch iscontinued, the affection expression level is increased, but if the touchis continued too persistently, the affection expression level may bereduced.

The affection expression level also changes depending on contactstrength. The affection expression level of a touch is “+1”, but becomesdouble that at “+2” when the touch is strong. When a touch isparticularly strong, it is seen as being a “hit”. At this time, “10” issubtracted, and the affection expression level is identified as “−9(=1−10)”. The same applying to a hug, the affection expression level ofa normal hug is “+10”, but the affection expression level when huggingtightly is double that at “+20”. The affection expression level of a hugstrong enough to throttle is three times that of a normal hug, butfamiliarity decreases as the hug is unpleasant. A strong expression ofaffection is not necessarily pleasant for the robot 100, or in otherwords, is not necessarily a trigger for familiarity increasing.

Not being limited to a single affection expression level based on aresponsive action, various motions are correlated in a motion selectiontable in accordance with an amount of change in an accumulated value ofaffection expression levels in a predetermined period, or an accumulatedvalue per unit time. The operation control table 150 refers to themotion selection table, and selects a motion in accordance with anaffection level.

When a pleasant action is detected, the familiarity managing unit 220raises familiarity with respect to the user. When an unpleasant actionis detected, the familiarity managing unit 220 reduces familiarity withrespect to the user. Also, when an unpleasant action continues, and whenan unpleasant action such as violence is recognized, the operationcontrol unit 150 issues an instruction for an action of moving away fromthe user. Basically, “pleasant and unpleasant” affect behavioralcharacteristics via familiarity.

Furthermore, the emotion estimating unit 250 may determine an emotion incombination with an expression recognition by the expression recognizingunit 230. When an angry face and a laughing face can be recognized, anexpression of a user can be more accurately determined. Even when anaffection level identified based on a contact aspect is “+1”, “−3” maybe added to the affection expression level when the user's expression isan angry expression, and the affection expression level determined to be“−2”. In the same way, even when an affection expression level whenkicked by a user is “−50”, it may be determined that the kick wasunavoidable rather than deliberate when the user displays a dismayedexpression, and the affection expression level may be corrected to “−20”by “+30” being added to the affection expression level.

When an affection expression level is high, or when an accumulated valueof affection expression levels increases, the robot 100 selects a motionof hovering around in a vicinity of an owner, asking for a hug, or thelike. When an affection expression level is low, the robot 100 may sitquietly in a place a little distanced from an owner. As behavioralcharacteristics of the robot 100 change in accordance with an emotion ofan owner, the owner can recognize that the robot 100 may be adjusting tothe owner in its own way. Basically, the affection expression levelmomentarily affects the behavioral characteristics of the robot 100.

When an affection expression level is high, the robot 100 may actenergetically by execution of a motion being accelerated, and when anaffection expression level is low, speed of executing a motion may berestricted. The interval may also be adjusted. A motion may be caused tochange by one portion of unit motions configuring the motion beingreplaced or omitted in accordance with the affection expression level.

In this way, what kind of physical contact (contact aspect) is beingperformed is determined from the touch sensor 400, and the affectionexpression level is calculated in accordance with the contact aspect. Astrong contact indicates a strong affection, but a contact that is toostrong cannot be said to be affection. As physical contact is carriedout as a manifestation of a natural emotion of a human, physical contactis a powerful source of information when estimating an emotion of anowner. Various setting methods, such as an action of stroking the headhaving an affection expression level of “+3”, an action of huggingtightly, or specifically, an action of making contact with a wide regionof the lower back portion, having an affection expression level of“+20”, and an action of hugging tightly and bringing a cheek close, orspecifically, an action of making contact not only with a wide region ofthe lower back portion but also the chest portion and the head portion,having an affection expression level of “+50”, are conceivable inaddition to the heretofore described examples.

To summarize, familiarity and an affection expression level areidentified in accordance with a responsive action. Familiarity is aparameter that reflects a pleasant action and an unpleasant action, orin other words, a degree of pleasantness for the robot 100. The robot100 increases familiarity with respect to an owner that performs apleasant action, and reduces familiarity with respect to an owner thatperforms an unpleasant action. In time, a difference in familiarity hasan effect on behavioral characteristics of the robot 100. Meanwhile, anaffection expression level estimates an emotion of an owner from aresponsive action, particularly a contact action, with respect to therobot 100. The operation control unit 150 selects various motions inaccordance with the affection expression level. Normally, it is oftenthe case that a contact action with a high affection expression level isa pleasant action.

A person's action of “touching”, so-called physical contact, is suchthat a feeling of the person touching toward the person touched iseasily expressed. It is said that a feeling that a subordinate is cuteis expressed in an action of stroking a head. It is said that there is amentality of wanting to be nearer a companion in an action of touching acheek. For example, the robot 100 may select a motion of performing agesture of wanting to be indulged by an owner when the head is stroked.When a cheek is touched, the robot 100 may select a motion of bringingthe body into contact with the owner, and performing a gesture of askingfor a hug.

FIG. 9 is a flowchart showing a process when a contact is detected.

When no person can be confirmed in the periphery of the robot 100 (N ofS10), or in other words, when no person can be filmed by the camera 402and when no moving heat source can be detected by the thermosensor 404,the sensitivity control unit 174 restricts the sensitivity of the touchsensor 400 (S22). Restriction of sensitivity is realized by a drop indetection voltage. As contact detection by the touch sensor 400 isunneeded when nobody is present, restricting the sensitivity of thetouch sensor 400 contributes to saving power. Restricting sensitivity atthis point may mean turning off (deactivating) the touch sensor 400.

When a person is detected (Y of S10), the sensitivity control unit 174sets the sensitivity of the touch sensor 400 to a normal sensitivity(hereafter called a “basic sensitivity”) (S12). When no contact with thetouch sensor 400 is detected (N of S14), a subsequent process isskipped.

When a contact is detected (Y of S14), the recognizing unit 156identifies a contact aspect (contact place, contact strength, andcontact time), and the emotion estimating unit 250 identifies anaffection expression level (S16). The response recognizing unit 228determines whether a responsive action is pleasant or unpleasant, andthe familiarity managing unit 220 updates familiarity in accordance witha determination result (S18). Also, the operation control unit 222selects one from among a multiple of motions in response to the contactaction (S20). For example, when a cheek is touched, the operationcontrol unit 222 may execute a motion of sitting on the spot and raisingthe arm 106.

It is supposed that when the robot 100 is wearing the clothing 180, thedetection sensitivity of the touch sensor 400 decreases because of theclothing 180. When the clothing detecting unit 172 detects a wearing ofthe clothing 180, the sensitivity control unit 174 may increase thesensitivity of the touch sensor 400 to or above the basic sensitivity.The sensitivity of the touch sensor 400 may be adjusted in accordancewith a kind or number of layers of the clothing 180. The server 200 orthe robot 100 may have a data table in which clothing ID and a preferredsensitivity of the touch sensor 400 are correlated in advance.

Heretofore, the robot 100, and the robot system 300 including the robot100, have been described based on an embodiment.

Action selection that cannot be patterned using one or more action maps,is difficult to predict, and is animal-like, is expressed.

An action of touching is a most primitive and basic means ofcommunication. In the robot 100, the main body frame 310 corresponds tobone, the outer skin 314 to flesh, and the covering skin 406 to skin,and the touch sensor 400 corresponds to a nerve. As shown in FIG. 1, thetouch sensor 400 covers a wide region of the body 104 of the robot 100.Because of this, the robot 100 can detect contact on various places.Also, contact strength can also be recognized by two layers, those beingthe first layer touch sensor 400 a and the second layer touch sensor 400b, being adopted. As the touch sensor 400 is formed with a plastic filmas a base, the touch sensor 400 can be affixed along the curved body104.

The robot 100 is rounded and soft, and has an appropriate weight. Also,the robot 100 incorporates a heat source such as the battery 118,because of which warmth is transmitted to the body 104 of the robot 100.As a result of this, a user feels a desire to touch or hug the robot100. By the touch sensor 400 being installed along the rounded and softbody 104, the robot 100 can recognize a large variety of contactactions.

When making contact gently, familiarity rises, in accordance with whichthe behavioral characteristics of the robot 100 also change. Meanwhile,when making contact roughly, familiarity decreases. An affectionexpression level (an estimated value of the strength of a companion'saffection) is identified in accordance with the way of making contact,and the robot 100 selects various motions in accordance with theaffection expression level. Not only does the robot 100 have the body104 that a user feels a desire to touch, but also there is anarrangement such that empathy increases by touching, because of whichinterchange between a user and the robot 100 is easily promoted further.

The invention not being limited to the heretofore described embodimentor a modified example, components can be changed or embodied withoutdeparting from the scope of the invention. Various inventions may beformed by a multiple of the components disclosed in the heretoforedescribed embodiment or the modified example being combined asappropriate. Also, some components may be eliminated from the total ofcomponents shown in the heretofore described embodiment or the modifiedexample.

Although a description has been given assuming that the robot system 300is configured of one robot 100, one server 200, and the multiple ofexternal sensors 114, one portion of the functions of the robot 100 maybe realized by the server 200, and one portion or all of the functionsof the server 200 may be allocated to the robot 100. One server 200 maycontrol a multiple of the robot 100, or a multiple of the server 200 maycontrol one or more of the robot 100 in cooperation.

A third device other than the robot 100 and the server 200 may manageone portion of functions. A collection of the functions of the robot 100and the functions of the server 200 described in FIG. 7 can also becomprehensively grasped as one “robot”. It is sufficient that a methodof distributing the multiple of functions needed in order to realize theinvention with respect to one or multiple items of hardware isdetermined with consideration to the processing capability of each itemof hardware, specifications required of the robot system 300, and thelike.

As heretofore described, “the robot in a narrow sense” is the robot 100excluding the server 200, but “the robot in a wide sense” is the robotsystem 300. It is thought that there is a possibility of many functionsof the server 200 being integrated in the robot 100 in future.

In this embodiment, the first layer touch sensor 400 a and the secondlayer touch sensor 400 b are both hidden from the exterior by thecovering skin 406 and the like. Because of this, a user is not aware ofthe existence of the touch sensor 400. The first layer touch sensor 400a may be installed on the covering skin 406. In this case, the firstlayer touch sensor 400 a is visible from the exterior, but there is anadvantage in that detection sensitivity increases.

There may be three or more layers of the touch sensor 400, and there maybe one layer. In the case of one layer, this may be the second layertouch sensor 400 b only, or may be the first layer touch sensor 400 aonly. Also, the touch sensor 400 may be installed as an intermediatelayer of the outer skin 314.

In addition to an electrostatic capacitance sensor as a sensor fordetecting contact, a method such that the covering skin 406 is formed ofapiezoelectric fabric is also conceivable. By a polylactic acid fiberbeing used as a piezoelectric body fabric and a carbon fiber being usedas an electrode, the piezoelectric fabric detects a charge generated bythe polylactic acid fiber. In addition to this, a large variety ofcontacts may be detected by combining a thermocouple, a pressure sensor,a strain gauge, and the like.

The sensitivity of the touch sensor 400, which is an electrostaticcapacitance sensor or the like, may be caused to differ in accordancewith an installation place. For example, the sensitivity of the touchsensor 400 installed in the abdomen may be low, and the sensitivity ofthe touch sensor 400 installed in the buttocks or the arm may be set tobe high. Sensitivity may be adjusted in accordance with a magnitude ofdetection voltage, or sensitivity may be changed by causing a density ofthe electrode wires in the electrostatic capacitance sensor to differ.By changing sensitivity in accordance with place, a skin sense peculiarto the robot 100, for example, the abdomen being insensitive and thebuttocks being sensitive, can be realized. Also, reducing thesensitivity of the touch sensor 400 in one portion of places, ratherthan the whole of the touch sensor 400 being of a high sensitivity, alsocontributes to saving power.

A frequency of touching the robot 100 may affect the behavioralcharacteristics of the robot 100. For example, the robot 100 whosebuttocks are often touched in a predetermined period after manufacturemay recognize the buttocks being touched as a pleasant action or anexpression of affection even after the predetermined period elapses.Meanwhile, the robot 100 whose buttocks are infrequently touched in thepredetermined period may recognize the buttocks being touched as anunpleasant action or an insult (an action with a low affectionexpression level) after the predetermined period elapses. In this way, amethod of determining “pleasant or unpleasant” may be changed inaccordance with a contact aspect. That is to say, the robot 100 whose“upbringing” changes in accordance with a contact aspect in infancy canbe realized.

In addition to contact place, contact strength, and contact time,pleasantness may be determined in accordance with contact frequency or atime band in which contact is performed. For example, although a cheekbeing touched is a pleasant action, this may change partway through tobeing recognized as an unpleasant action when the cheek is touched witha high frequency. Also, being touched during charging may be recognizedas an unpleasant action.

Pleasantness in this embodiment has two values, those being “pleasant”and “unpleasant”, but there may be three or more values. For example,pleasantness may be categorized into five steps, those being “extremelypleasant”, “fairly pleasant”, “average”, “fairly unpleasant”, and“extremely unpleasant”. Pleasantness may be indicated as a continuousvalue. For example, when the abdomen is 2 points, touching strongly is−4 points, and a contact time of 3 seconds or more is 1.5 times,pleasantness in a case in which the abdomen is touched strongly for 3seconds or more may be calculated to be −3 points, as (2−4)×1.5=−3. Thefamiliarity managing unit 220 updates familiarity in accordance withpleasantness. Also, a motion corresponding to when pleasantness reachesa predetermined value or greater, or a predetermined value or less, maybe correlated in advance.

Lifting in the Arms Motion

FIG. 10 is a functional block diagram of the robot system 300 in a firstworking example.

In the robot system 300 of the first working example, the dataprocessing unit 202 of the server 200 includes a state managing unit 224in addition to the position managing unit 208, the map managing unit210, the recognizing unit 212, the operation control unit 222, and thefamiliarity managing unit 220. The state managing unit 224 managesvarious kinds of internal parameter indicating various kinds of physicalstate, such as a charging rate, an internal temperature, and aprocessing load of the processor 122. The state managing unit 224includes an emotion managing unit 234.

The emotion managing unit 234 manages various emotion parametersindicating an emotion (loneliness, curiosity, a desire for recognition,and the like) of the robot 100. These emotion parameters are constantlyfluctuating. The importance of a multiple of action maps changes inaccordance with an emotion parameter, a movement target point of therobot 100 changes in accordance with the action maps, and the emotionparameter changes in accordance with movement of the robot 100 and thepassing of time.

For example, when an emotion parameter indicating loneliness is high,the emotion managing unit 234 sets a weighting coefficient of an actionmap that evaluates a place in which the robot 100 feels at ease to behigh. When the robot 100 reaches a point on the action map at whichloneliness can be eradicated, the emotion managing unit 234 reduces theemotion parameter indicating loneliness. Also, the various kinds ofemotion parameter also change in accordance with a responsive action.For example, the emotion parameter indicating loneliness decreases whenthe robot 100 is “hugged” by an owner, and the emotion parameterindicating loneliness increases gradually when the robot 100 does notvisually recognize an owner for a long time.

The robot 100 includes a speech output unit 134. The speech output unit134 outputs speech. The robot 100 in this embodiment can output wordlessspeech like an animal's cry, such as a yawn, a shriek, or a purr, usingthe speech output unit 134.

The internal sensor 128 of the robot 100 includes an acceleration sensor138, a gyro sensor 140, and an internal temperature sensor 144, inaddition to the touch sensor 400, the camera 402, and the thermosensor404. The recognizing unit 156 recognizes a lifting in the arms, aputting down while holding, and a falling of the robot 100, using theacceleration sensor 138. The recognizing unit 156 determines a postureof the robot 100 using the gyro sensor 140. The internal temperaturesensor 144 detects the internal temperature of the robot 100.

The data processing unit 136 of the robot 100 includes a pupil controlunit 152 and a speech control unit 154 in addition to the recognizingunit 156, the operation control unit 150, the clothing detecting unit172, and the sensitivity control unit 174. The speech control unit 154selects speech to be output from the speech output unit 134 from amultiple of speech patterns. The pupil control unit 152 generates an eyeimage (to be described hereafter), and causes the eye image to bedisplayed on the eye 110.

In the first working example, the operation control unit 150 of therobot 100 selects a motion in accordance with a kind (to be describedhereafter) of lifting in the arms (hugging). An activation conditionthat forms a trigger for motion execution and a state condition thatindicates a situation when the activation condition is satisfied aredefined in advance, and various kinds of motion are executed asresponsive behavior selected based on the activation condition and thestate condition. The activation condition may be, for example, an eventsuch as being stroked or spoken to by an owner, or may be an internalphenomenon such as when a value of the emotion parameter indicatingloneliness exceeds a threshold. In the first working example, variouskinds of activation condition are satisfied by being hugged, and by thekind of hug. It is sufficient that the state condition is a conditionindicating an internal or external situation when the activationcondition is satisfied, such as being watched closely by an owner, amultiple of users being in the periphery, or a room temperature being apredetermined temperature or higher.

The operation control unit 150 may identify one motion based on anactivation condition and a state condition, or may select one motionfrom a multiple of motions based on a selection probability. Forexample, it is assumed that 10%, 20%, and 15% are set as selectionprobabilities of motions M1 to M3 respectively for an activationcondition E1 and a state condition S1. In this case, the motions M1 toM3 are selection candidates when the activation condition E1 and thestate condition S1 are satisfied, but a 55% probability of nothing beingexecuted also exists.

FIG. 11 is an external view of the eye image 176.

The eye 110 of the robot 100 is formed as a display on which the eyeimage 176 is displayed. The pupil control unit 152 generates the eyeimage 176 to include a pupil image 178 and a periphery image 168. Thepupil control unit 152 also displays the eye image 176 as a movingimage. Specifically, the pupil control unit 152 represents a line ofsight of the robot 100 by moving the pupil image 178. Also, a blinkingoperation is executed at a predetermined timing. The pupil control unit152 represents a large variety of movements of the eye image 176 inaccordance with various operation patterns. A monitor of the eye 110desirably has a curved form, in the same way as a human eyeball.

The pupil image 178 includes a pupillary region 258 and a corneal region163. Also, a catch light 170 for expressing a reflection of externallight is also displayed in the pupil image 178. Rather than shiningowing to a reflection of external light, the catch light 170 of the eyeimage 176 is an image region expressed as a high-luminance region by thepupil control unit 152.

The pupil control unit 152 can move the pupil image 178 vertically andhorizontally on the monitor. When the recognizing unit 156 of the robot100 recognizes a moving object, the pupil control unit 152 expresses a“gaze” of the robot 100 by orienting the pupil image 178 toward themoving object.

The pupil control unit 152 not only moves the pupil image 178 relativeto the periphery image 168, but can also represent a half-closed eye ora closed eye by causing an eyelid image to be displayed. The pupilcontrol unit 152 may represent an aspect of the robot 100 sleeping usinga closed eye display, or may represent an aspect of the robot 100 beingin a half-asleep state, that is, a state of nodding off to sleep, bycovering three-quarters of the eye image 176 with the eyelid image, thenshaking the eyelid image.

FIG. 12 is a first conceptual view of when hugging the robot 100.

The robot 100 has the body 104, which is rounded, soft, and pleasant totouch, and an appropriate weight, and recognizes a touch as a pleasantaction, because of which a user is easily caused to feel an emotion ofwanting to hug the robot 100.

In FIG. 12, the robot 100 and an owner are facing each other. Also, therobot 100 is being hugged in a vertical direction. Hereafter, this kindof hug will be called a “confronting vertical hug”. Also, the robot 100being tilted sideways and hugged will be called a “horizontal hug”. Therecognizing unit 156 distinguishes an orientation (posture) of a hugusing the gyro sensor 140. The recognizing unit 156 may distinguish aposture from an orientation of an image filmed by the camera 402, or maydistinguish a posture based on contact aspects in each region of therobot 100 surface detected by the touch sensor 400. Of course, a postureof the robot 100 may be distinguished by combining results of detectionsby these detection means.

FIG. 13 is a second conceptual view of when hugging the robot 100.

In FIG. 13, an owner is hugging the robot 100 from behind. The robot 100is being hugged in a vertical direction. Hereafter, this kind of hugwill be called a “rear vertical hug”. The recognizing unit 156distinguishes a kind of hug using a neural network, with various kindsof detection information from the gyro sensor 140, the camera 402, thethermosensor 404, and the touch sensor 400 as input information. Forexample, the recognizing unit 156 distinguishes between a vertical hugand a horizontal hug using the gyro sensor 140, and can distinguish thata hug is not a rear vertical hug when a face, a chest portion, or thelike of an owner appears in close range in front of the robot 100. Inaddition to this, categories of various hugs, such as a hug such thatthe robot 100 is lifted onto a shoulder and hugged, or a hug such thatan owner who is lying down places the robot 100 on an abdominal portionand hugs the robot 100 tightly, may be defined. Also, horizontal hugsmay be defined divided into a “right-facing horizontal hug” and a“left-facing horizontal hug” in accordance with whether the head portionof the robot 100 is positioned on a right-arm side or a left-arm side ofan owner. Furthermore, an “upward-facing horizontal hug” and a“downward-facing horizontal hug” may be defined depending on whether theabdomen portion of the robot 100 is facing upward (a ceiling side) orfacing downward (a floor side).

Hereafter, a description will be given with the heretofore describedconfronting vertical hug, horizontal hug, and rear vertical hug assubjects.

FIG. 14 is a data structure diagram of a motion selection table 190.

The motion selection table 190 is stored in the motion storage unit 232of the server 200 or the motion storage unit 160 of the robot 100. Anactivation condition, a state condition, and a motion are correlated inthe motion selection table 190. The motion selection table 190 of FIG.14 shows motions selected in accordance with various kinds of statecondition when the activation condition E1 is satisfied. The conditionE1 is satisfied, for example, when the robot 100 is laterally hugged. Anactivation condition is prepared for each kind of hug, such as theconfronting vertical hug and the rear vertical hug. Herein, theoperation control unit 150 of the robot 100 selects the multiple ofmotions M1 to M3 expressing pleasure (hereafter, a motion expressingpleasure will be called a “motion of delight”), or a motion M4expressing sleep, in accordance with state conditions S1 to S4.

The state condition S1 indicates a state wherein the robot 100 is notbeing touched other than by contact from a hug, that is, a state ofsimply being hugged only. In this case, the touch sensor 400 is notdetecting a touch that is a movement by an owner. The state condition S2is such that the abdomen portion being stroked is defined, the statecondition S3 is such that the head portion being stroked is defined, andthe state condition S4 is such that the abdomen portion being repeatedlypatted gently is defined.

The motion of delight M1 correlated to the state condition S1 is a unitmotion of staring at an owner. The motion of delight M2 correlated tothe state condition S2 is a compound motion including unit motions ofdirecting the line of sight toward an owner who is hugging, moving thearm 106, and shaking the head to left and right while emitting a soundof delight. The motion of delight M3 correlated to the state conditionS3 is a compound motion including unit motions of directing the line ofsight toward an owner and shaking the head to left and right. A motionexpressing sleep is correlated to the state condition S4.

When the state condition S1 is satisfied when the activation conditionE1 is satisfied, the operation control unit 150 selects the motion ofdelight M1. That is, the robot 100 moves each portion in accordance withthe motion of delight M1 when hugged horizontally. The operation controlunit 150 may always select the motion of delight M1 when the statecondition S1 is satisfied, or may select the motion of delight M1 at apredetermined selection probability (less than 100%). Also, asheretofore described, the operation control unit 150 may select a motionof delight from the multiple kinds of motion of delight when the statecondition S1 is satisfied. By the operation control unit 150 selecting amotion on a probability basis, the same motion always being executedwhen a certain condition is satisfied is prevented, and animal-likebehavior can be realized.

In this way, the operation control unit 150 selects a motion inaccordance with a kind of hug, particularly a posture when being hugged,and in accordance with which region of the body surface is being touchedwith which kind of contact aspect in that posture. Not only theoperation control unit 150, but also the pupil control unit 152 causesthe eye image 176 to change as one portion of a motion, and the speechcontrol unit 154 outputs various items of speech as one portion of amotion.

Other than a hug, various phenomena are conceivable as a phenomenonforming a trigger for executing a motion, that is, an activationcondition. For example, the operation control unit 150 may cause amotion to change in accordance with a contact aspect of where the robot100 is touched by a user, and how strongly the robot 100 is touched.Other than this, the operation control unit 150 may select a motion withvarious phenomena, such as the upper back being stroked or a chin beingstroked, as an activation condition. Also, an activation condition maybe defined based on an emotion parameter such as pleasure (delight),loneliness, fear, or a desire for attention. A state condition may besuch that a posture of the robot 100 and a contact aspect arecorrelated.

The pupil control unit 152 may express “agitation” by moving the eyeimage 176 little by little to left or right, and may express “interest”or “surprise” by enlarging the pupillary image 178. The operationcontrol unit 150 may express a “physical fussiness” by causing anactuator to stop in a predetermined position, or conversely, may express“lethargy” by stopping a supply of power to an actuator. The operationcontrol unit 150 may express “feeling good by being touched” or“ticklishness” by moving an actuator near a place touched by an ownerlittle by little.

The speech control unit 154 may express a “pleasant feeling” by emittinga voice indicating pleasure when the abdomen is lightly hit or strokedin a confronting vertical hug state. At this time, the familiaritymanaging unit 220 raises familiarity with respect to the owner, and theemotion managing unit 234 lowers the emotion parameter indicatingloneliness, whereby there is a change to a psychological state of“feeling at ease”. When stroking under the chin of the robot 100 whenthe robot 100 is being hugged, various kinds of motion of delight suchthat the robot 100 also expresses pleasure, just as a dog or a catexpresses pleasure, may be selected. At this time, the pupil controlunit 152 may express a “pleasant feeling” by changing the eyelid imageof the eye image 176 to represent a half-closed eye.

When a predetermined time (hereafter called an “introduction time”)elapses from hugging the robot 100, the robot 100 may express abehavioral aspect of falling asleep (hereafter called a “sleepingexpression”). More specifically, when an owner hugs the robot 100, thespeech control unit 154 outputs a “yawn”, after which the operationcontrol unit 150 causes the robot 100 to gradually become lethargic byreducing the supply of power to each actuator. Subsequently, the pupilcontrol unit 152 causes the eye image 176 to close. At this time, thespeech control unit 154 may regularly output sleeping noises at a lowvolume. When a further predetermined time elapses after starting thesleeping expression, the operation control unit 150 may save power bychanging the processor 122 to a suspended state.

When a predetermined time (hereafter called a “sleeping time”) elapsesfrom the start of the sleeping expression or the shift to the suspendedstate, the operation control unit 150 causes the sleeping expression toend. At this time, the pupil control unit 152 causes the eye image 176to open. When a predetermined awakening event occurs, such as when thetouch sensor 400 detects a strong touch or when loud speech is picked upby the microphone, the operation control unit 150 or the like may causethe sleeping expression to end, despite being before the sleeping timeelapses. When the sleeping expression is ended, the processor 122returns from the suspended state to a normal operating state.

The introduction time may be changed in accordance with various kinds ofparameter shown below. When an owner lifting and hugging the robot 100sings a lullaby to the robot 100, or when the owner utters specificwords such as “good night” or “beddy bye”, the operation control unit150 may shorten the introduction time. When the robot 100 is hugged byan owner with familiarity of a predetermined value or greater, theoperation control unit 150 may shorten the introduction time.Alternatively, a setting may be such that the higher the familiarity,the shorter the introduction time becomes. According to this kind ofcontrol method, a feeling of ease at being hugged by an owner with highfamiliarity can be expressed by behavior. When the robot 100 is huggedby an owner with familiarity of a predetermined value or lower, theoperation control unit 150 need not execute the sleeping expression ofthe robot 100.

The operation control unit 150 may set the introduction time to beshorter the greater an amount of activity before a hug, for example, themagnitude of a supply of power to each actuator in a latestpredetermined period until being hugged, an amount of movement of therobot 100, an amount of power consumed, and the like. According to thiskind of control method, a behavioral expression of being liable tobecome sleepy when moving energetically can be performed. In addition tothis, the operation control unit 150 may set the introduction time to beshorter than normal when the value of the emotion parameter indicatingloneliness decreases and the mentality of the robot 100 is in a state of“feeling at ease”, when peripheral environmental noise is at apredetermined level or lower, when the room temperature is in apredetermined comfortable temperature range, for example, 15° C. to 25°C., or when the periphery is dark. In the same way, the operationcontrol unit 150 may set extra sleeping time for the robot 100 when therobot 100 is in a state of feeling at ease, when it is quiet and theroom temperature is appropriate, or when the amount of activity islarge. The robot 100 holds the time and date of shifting from thesuspended state to the normal state, and may refuse to sleep when apredetermined time has not elapsed from the previous sleeping state.

The sleeping expression is such that the robot 100 expresses animal-likebehavior, and a formation of attachment to an owner is realized.Meanwhile, the sleeping expression is also an expression of a functionof suspending the robot 100, and forms a trigger, that is, a startcommand of a function of suspending contact action by the owner withrespect to the robot 100. In general, a suspending function is startedby a user performing a direct operation such as a pressing a switch. Therobot 100 in this embodiment is such that a “hugging” action of an ownercontinuing for a certain period forms a trigger of the suspendingfunction. The hugging action is the same action as when putting a babyto bed, and can be carried out naturally by an owner. Because of this,when wanting the robot 100 to be quiet, an owner can put the robot 100to bed, that is, suspend the robot 100, by hugging the robot 100 andcrooning specific words such as “beddy bye”, as when putting a baby tobed.

The internal temperature sensor 144 regularly measures the internaltemperature of the robot 100. When the robot 100 is being hugged, theoperation control unit 150 may delay starting the sleeping expressionuntil the internal temperature drops to or below a predeterminedtemperature.

When an owner moves a finger left and right in front of the eye 110 ofthe robot 100, the pupil control unit 152 may cause the pupillary image178 to move left and right following the finger. Further, the operationcontrol unit 150 may cause the eye image 176 to shift to the sleepingstate after the left-right reciprocating operation of the pupillaryimage 178 has continued a few times. For example, an activatingcondition is defined as an owner holding up a finger in front of the eye110 after the owner utters the specific words “watch this”. A statecondition is defined as moving the finger left and right three times.When the activation condition and the state condition are satisfied, amotion of shifting to the sleeping state is executed. A movement, thatis, a gesture by an owner forms a trigger that causes the robot 100 toselect a motion. At this time, a management program executed in theprocessor 122 may shut down the functions of the robot 100. According tothis kind of control method, the robot 100 can easily be caused to stopby a gesture, without using a device such as a button.

Not being limited to a motion of delight expressing pleasure, theoperation control unit 150 can execute various motions. For example,when an activation condition E2 is satisfied, the operation control unit150 may execute a motion expressing fear. For example, the robot 100being lifted to a position higher than an owner's face, the robot 100falling from a high place, being subjected to violence, detecting anoise of a predetermined volume or greater, and the like, areconceivable as the activation condition E2. The recognizing unit 156recognizes a rise and a drop using the acceleration sensor 138. Also,the recognizing unit 156 determines whether or not the robot 100 hasbeen lifted above an owner's face using the camera 402. The recognizingunit 156 recognizes a violent action such as kicking or hitting usingthe touch sensor 400.

“Freezing”, whereby an actuator is fixed and maintained in apredetermined position, outputting a shrieking sound, “fainting, wherebythe eye is closed after turning off an actuator, “agitation”, wherebythe pupillary image 178 is shaken left and right, and the like, areconceivable as a motion expressing fear.

When the robot 100 is hugged, the operation control unit 150 may selecta motion of attempting to escape from the hug (hereafter, a motion ofrefusing involvement with an owner will be called a “refusal motion”). Arefusal motion may be defined as a combination of unit motions such as,for example, staring at the owner, emitting a voice, repeatedly movingthe arm 106, shaking the head left and right, repeatedly moving thefront wheel 102 in and out, shaking the trunk left and right, movingeach portion so as to cause the owner to feel that hugging is difficult,and the like. When the robot 100 cannot escape from the hug even byexecuting a refusal motion, the robot 100 may execute the sleepingexpression after the introduction time elapses. When the robot 100 ishit during a hug, the operation control unit 150 may select a refusalmotion after selecting a motion indicating surprise, such as looking inthe direction of the hit.

When the robot 100 is hugged, the operation control unit 150 may executea refusal motion such that an amount by which each kind of actuator canmove is large, and reduce the amount by which the actuators can movewith the passing of time, thereby expressing by behavior “an aspect ofgradually giving up and quietening down”. Also, after the robot 100quietens down, the pupil control unit 152 may express by behavior anaspect of “giving up on escaping” by shifting the line of sight of thepupillary image 178 from the user.

When movement of a user is not detected for a predetermined time orlonger by the camera 402 or the touch sensor 400 in a state in which therobot 100 is hugged, the operation control unit 150 reduces the amountby which the actuators can move. Further, when this kind of statecontinues for a predetermined time, the operation control unit 150 mayexecute a refusal motion. A complex behavioral expression can beperformed in that the robot 100 relaxes and entrusts the body when theowner does not move, but becomes bored of the hug and wants to move whenthe owner does not move for a long time.

When the robot 100 is touched when the front wheel 102 is out, theoperation control unit 150 executes a motion of orienting the body 104toward the user who has touched. Meanwhile, when the robot 100 istouched when the front wheel 102 is housed, the operation control unit150 may execute a motion of orienting the head toward the user, withoutmoving the body 104. In this way, the operation control unit 150 mayselect differing motions in accordance with the housing state of thefront wheel 102 when the robot 100 is touched.

When a back face of the body 104, for example the buttocks, are touched,the operation control unit 150 may express an aspect of the robot 100attempting to see the place that has been touched, but being confused bybeing unable to do so, by causing the body 104 to rotate. When the sameplace on the body 104 is touched continuously, the pupil control unit152 may express by behavior a “gesture of being bothered about beingtouched” by directing the line of sight to the place touched.Furthermore, when continuing to be touched in the same place, the robot100 may execute a predetermined motion such as bending the neck back,becoming lethargic, waving the arm 106, or emitting a yawn. In order toescape from the continuous touch, the operation control unit 150 maycause the robot 100 to move in a direction away from the user. When thehead is touched, the operation control unit 150 may execute a motion ofdisliking the touch by causing the neck to move. When a touch continues,the pupil control unit 152 may express an ill-tempered expression suchas a glare by directing the sensitivity control unit 174 toward theuser.

The touch sensor 400 may be installed in an upper half of the horn 112.Further, when the upper half of the horn 112 is touched, the operationcontrol unit 150 may select various refusal motions. For example, whenthe upper half of the horn 112 is touched for one second or longer ortouched twice or more, the operation control unit 150 may express acharacteristic of “hating to have the horn 112 touched” by escaping fromthe user. According to this kind of control method, the field of viewbeing blocked by the horn 112, in which the camera 402 (anomnidirectional camera) is mounted, being gripped is easily prevented.

What is claimed is:
 1. An autonomously acting robot, comprising: asensor configured to detect a contact by a user at a contact location ona body surface of the robot; a non-transitory computer readable mediumconfigured to store instructions; and a processor connected to thenon-transitory computer readable medium, wherein the processor isconfigured to execute the instructions for: identifying the detectedcontact as a contact type from a plurality of contact types based on acombination of the contact location and a contact strength of thedetected contact; determining an affection expression level based on theidentified contact type; updating a familiarity level associated withthe user based on the identified contact type; and controllingbehavioral characteristics of the robot based on the determinedaffection expression level.
 2. The autonomously acting robot accordingto claim 1, wherein the processor is further configured to execute theinstructions for: changing an emotion level of the robot in response tothe determined affection expression level, controlling the behavioralcharacteristics of the robot based on the emotion level.
 3. Theautonomously acting robot according to claim 1, further comprising: anelastic outer skin on an external surface of the robot, wherein thesensor is configured to detect the contact by the user at a contactlocation on the elastic outer skin.
 4. The autonomously acting robotaccording to claim 3, wherein the sensor is shaped along a shape of theexternal surface of the robot.
 5. The autonomously acting robotaccording to claim 3, wherein the sensor comprises a first portion on anouter surface of the elastic outer skin, and a second portion betweenthe external surface of the robot and an inner surface of the elasticouter skin.
 6. The autonomously acting robot according to claim 1,wherein the processor is further configured to execute the instructionsfor reducing a detection sensitivity of the sensor in response to adetermination that no user is in a peripheral region surrounding therobot.
 7. The autonomously acting robot according to claim 1, whereinthe processor is further configured to execute the instructions forgenerating a notification operation in response to a second sensor fordetecting external information being impeded during detecting of thecontact by the user.
 8. An autonomously acting robot, comprising: asensor configured to a contacted by a user; a clothing detectorconfigured to detect a wearing of clothing by the robot; anon-transitory computer readable medium configured to storeinstructions; and a processor connected to the non-transitory computerreadable medium, wherein the processor is configured to execute theinstructions for: selecting a motion of the robot based on the detectedcontact; controlling a detection sensitivity of the sensor based on adetermination of whether the robot is wearing clothing; and a drivemechanism configured to execute the selected motion.
 9. The autonomouslyacting robot according to claim 8, wherein the processor is furtherconfigured to execute the instructions for: identifying the detectedcontact as a contact type from a plurality of contact types based on acombination of the contact location and a contact strength of thedetected contact; determining an affection expression level based on theidentified contact type; and controlling behavioral characteristics ofthe robot based on the determined affection expression level.
 10. Theautonomously acting robot according to claim 8, wherein the processor isfurther configured to execute the instructions for: changing an emotionlevel of the robot in response to the determined affection expressionlevel, controlling the behavioral characteristics of the robot based onthe emotion level.
 11. The autonomously acting robot according to claim8, further comprising: an elastic outer skin on an external surface ofthe robot, wherein the sensor comprises a first portion in the elasticouter skin.
 12. The autonomously acting robot according to claim 11,wherein the first portion of the sensor comprises a curved sensor. 13.The autonomously acting robot according to claim 11, wherein the secondcomprises a second portion between the external surface of the robot andthe elastic outer skin.
 14. The autonomously acting robot according toclaim 8, wherein the processor is further configured to execute theinstructions for reducing a detection sensitivity of the sensor inresponse to a determination that no user is in a peripheral regionsurrounding the robot.
 15. The autonomously acting robot according toclaim 8, wherein the processor is further configured to execute theinstructions for generating a notification operation in response to asecond sensor for detecting external information being impeded duringdetecting of the contact by the user.
 16. An autonomously acting robot,comprising: a sensor configured to detect a contact by a user on a bodysurface of the robot at a contact location; a non-transitory computerreadable medium configured to store instructions; and a processorconnected to the non-transitory computer readable medium, wherein theprocessor is configured to execute the instructions for: recognizing alifting or hugging of the robot, categorizing aspects of the lifting orhugging, into a plurality of contact types, based on the contactlocation and a strength of the contact, identifying one contact type ofthe plurality of contact types based on the contact location and thestrength of the contact after lifting or hugging of the robot; selectinga motion of the robot based on the identified one contact type; and adrive mechanism configured to execute the selected motion.
 17. Theautonomously acting robot according to claim 16, wherein the processoris further configured to execute the instructions for: detecting aposture of the robot during the lifting or hugging of the robot, andselecting the motion based on the detected posture of the robot.
 18. Theautonomously acting robot according to claim 16, wherein the processoris further configured to execute the instructions for causing a pupilimage displayed on an eye of the robot to change based on a duration ofthe lifting or hugging of the robot.
 19. The autonomously acting robotaccording to claim 17, wherein the processor is further configured toexecute the instructions for causing the pupil image to close inresponse to the duration of the lifting or hugging continuing for apredetermined time.
 20. The autonomously acting robot according to claim16, further comprising: an elastic outer skin on an external surface ofthe robot, wherein the sensor comprises a first portion in the elasticouter skin.